Shopify subscriber destination shows the original list again after Update Settings

Hi Klaviyo Community,

We need help verifying a destination-list change in our Shopify integration.

We attempted to change the email subscriber destination from our original list (“List A”) to our intended welcome-series list (“List B”). Both are actual lists, not segments, and both use single opt-in.

### What happened

- We selected List B and clicked “Update Settings” in two separate attempts.

- After each attempt, the selector displayed List B, including after reloading the integration settings page.

- A later inspection showed List A again. We have not established whether the updates were successfully saved server-side or why the displayed selection changed.

- Two historical test subscriptions through our native Shopify footer newsletter form became SUBSCRIBED in Shopify and Klaviyo, but both joined List A. We completed the Shopify email confirmations. The second test was submitted after the second update attempt.

- For the second profile, the “Subscribed to Email Marketing” event identifies INTEGRATION_SHOPIFY / Customer Webhook and references List A. A separate “Subscribed to List A” event confirms membership.

### Latest read-only verification

- The Shopify integration is Enabled, and “Sync your Shopify email subscribers to Klaviyo” is checked.

- The destination selector still displays List A. We did not save any settings or submit new test subscriptions during this check.

- We verified the connected store and that the integration settings and test profiles belong to the same Klaviyo account.

- Our intended welcome flow is triggered by addition to List B. The flow and its three email actions are Live; List A returned no associated flow triggers in our API check.

- We have not verified flow entry, message sends, or delivery for the historical test profiles. Live status alone does not confirm those outcomes.

- No pending confirmation dialog or save error was identified during the checks.

### Questions

1. What success confirmation should appear after “Update Settings”?

2. Is there a separate confirmation step or prerequisite for saving the Shopify subscriber destination?

3. Is there a supported way for the account owner to verify the destination list actually stored by the integration, beyond reading the selector?

4. Has anyone seen this behavior, and what diagnostic steps would you recommend before another update or controlled subscription test?

We have paused further updates and tests while investigating. We are looking for diagnostic guidance before changing permissions, reinstalling the integration, moving profiles, or modifying the welcome flow.

We have not opened a private support ticket for this issue. We are keeping customer information and account identifiers out of this public post; detailed evidence would only be shared through an official private support channel if available.

Thank you!